Improvement in apparatus and processes for preserving wood



A ZSheets-Sheet1,. I. HAYFORD.

APPARATUS AND PROGESSFOR PRESERVING WOOD.

No. 194,773. I Patented Sept. 4,1877.

N- PETERS, PHOTO-L'THDGNAPHEH. WASHINGTON D.

2 She ets-Sheet2.

I. HAYFURD. APPARATUS AND PROCESS FOR PRESERVING WOOD.

N.'194,7.7,3, Patented Sept. 4,1877.

v Fly. 3.

74567265563. Imam/07.

N. PETERS. FHOTU-LIYHOGRAPHEW, WIf-SHINGTON, D, C

UNITED STATES PATENT OFFIGE.

IRA HAYFORD, on BOSTON,MASSACHUSETTS.

IMPROVEMENT INAPPARATUS AND PROCESSES'FOR PRESERVING wooo.

Specification forming. part of Letters Patent No. 194,773, datedSeptember 4,1877 application filed June 2,1877.

Tooll whom it may concern Be it known that LIEA HAYFORD, of Boston,

Suffolk county, Massachusetts, have invented certain new and usefulImprovements in Apparatus for Treating Wood, of which the following is aspecification:

- In my present apparatus I employ a reser- "voir or chamber forreceivingand treating a suitablesource is employed in connection withthe above, andthe whole operating substantially as hereinafterexplained.

" The apparatus is provided with means for creating a vacuum in saidchamber after saturation of the wood by the steam and the withdrawal ofthe vapors of the latter, in order that the pores and cells of the woodmay be distended and readily absorb the preserving agent, and with meansfor continuously reintroducing the preserving agent tothetreatingchamber until the wood becomes saturated to the desiredextent, together with means for enveloping the wood at thesame time in ajacket of air to avoid checking and splitting.

The drawings accompanying this specification represent, in Figure 1,a'plan; in Fig. 2, an endelevation; in Fig. 3, a horizontal section; andin Fig. 4, a cross-section of an ap-- paratus, embodying myimprovements. Fig.- 5 is' an elevation of the front portion of thepreserving-retort, with the pipes connected therewith.

In these drawings,- A represents a steamboiler, from which I obtainsteam employed in the apparatus; while B represents the closed cylinderor tank to contain the creosote or other material with which the wood isto be charged; and J, a second tank or receiver, which constitutes thechamber in which the wood is treated, the latter being provided at oneor both ends with a door, by which the wood is'introduced into theinterior. I i Krepresents an air-pump disposed immediately adjacent tothe boiler A and tank B, and constructed with an annular waterchamber,L, surrounding itsair-cylinder, to contain a quantity of water and keepthe interior of the air-cylinder cool, the steam-cylinder and piston ofthis pump being shown at M and N, respectively, and the air-cylinder andpiston at OandR, j I

Suitable inlet and outlet pipes and cooks are combined with thewater-chamber L, by which water from a suitable source is allowed .tocirculate through saidchamber, and thereby maintain a low temperaturewithin the cylinder to counteract the heat resulting from thecompression of the air in the latter and of the vapors issuing therefromEach end .of the aircylinder O communieateswith a bent pipe, Q or Q, theoutlet 0 and P of each pipe being provided Witha cook, 12 or 1 3, bywhich air may be allowed to enter the cylinder, while the two pipesbetween the. cooks and cylinder are united by and communicate with a L-shaped pipe, 0, the upright portion of-this pipe being provided with acook, 10, and ex-f tending by a horizontal portion, 0 into thewood-preserving chamber J.

. When the 00011312 and, 13 are closed and,

the pump is inoperation, a powerful draft or: suction takes placethrough the pipes Q, Q, and 0 from the chamber J into the air-cylinder Oof the pump, andexhausts through a pipe, D, leading from said cylinder.This ex-- haust-pipe extends vertically from the pumpcylinder, andcontinues by a horizontal- .por-.

tion, D the outlet of the latterybeing fur: nished with a cock, 11. I iv From the horizontal portion'Di-of the'pipe D rises a continuation orprolongation in the form of a bent pipe, D, the upright part of which isfurnished with acock, 9, while the horizontal portion extends over thechamber J downward in rear of it, and communicates ber J, the uprightportion D of said pipe D in rear of said-cham berJ being furnished with"a cook, 21, and the pipe D being furnished with a'cock, 8.. The barrel Risco'ntrac ted at its outlet, asshown at S,.and is prolonged into a bentpipe, 11, which extends upward and over the chamber J, thence downwardinto the latter by an upright portion, H", and terminates withinsaid'chamber J in one or more open or foraminous branches, T T, the saidupright part H having a cock, 17, while its upper horizontal part has acock, 18. The upright portion H of the pipe H rises above and extendshorizontally by a portion, E, over the branch and is provided with acock, 16, such portion E extending downward and entering andcommunicating with the lower part of the interior of the tank B.

A steam-conduit, I, leads from the boiler A into the lower part of thechamber J, and is providedlwith a cock, 7, and, after describing severalturns or coils within the chamber J, to obtain a largeheat-radiatingtsurface, makes its exit from such chamber by a horizontalportion, U, which at its extremity is open to the atmosphere andfurnished with a cock, 4:. Between the cock 4 and the chamber J thehorizontal portion U of the pipe I is continued upward by an extension,V, and enters and communicates with the upper part of the interior ofsaid chamber J, and is provided outside of the chamber with a cock, 3.The steam-conduit I has a branch or extension, 2,

"which enters the valve chamber W of'the steam-cylinder of the pump K,and is furnished with a cock, 5, While the main part of the conduit I,near to the boiler, is provided with a'cock,3;. Furthermore, thesteam-conduit [has a second extension or branch, X, which extends to andenters the tank B, and, after coursing about the'interior of the latter,makes its exit therefrom and discharges into the atmosphere,except whenclosed by a cook, 22., which is-attached to it.

From the barrel R of the injector R, and communicating with itsinterior, extends a horizontal pipe, F, which is furnished close to thebarrel with a check-valve opening toward said barrel, and with a cook,19, outside of such check-valve, such pipe F extending upward into andcommunicating with'the interior of the chamber J by an upright branch,Z,

which is furnished with a cock, 5, while the horizontal part of suchpipe F joins and com municates with the horizontal pipe H, one end ofwhich is open to the asmosphere, except when closed by cock 6 applied toit, while its other end is continued upwardby an extension, F, andenters the upper part of the interior of the tank B.

A branch pipe, D connects at one end with the pipe D and at the otherend with the interior of the tank B, and is furnished with a cook, 14. l

- The, operation of thisapparatus is as follows: Supposing steam to beup in the boiler, a proper quantity of creosote or other preservingtluid placed in the tank B, and the desired'quantity of wood to betreated placed within the chamber J, and the doors of the latter closed,the cooks i, 1}, 3, 5,6, 7, 8, 9, 12, and 13 being open, and all therest hereinbefore named shut, with the exception of those applied to thecirculating-pipe of the waterchamber of the pump-cylinder, which, ofcourse, are alwaysopen when the apparatus is in operation. Steam fromthe boiler passes through pipe I into theinterior of the chamber J, and,acting upon the wood, serves to soften the latter and expand its poresand vaporize the sap, which then escapes, while at the same time air isdriven from the aircylinder of the pump through the pipe D D D, 850.,into the interior of the chamber J with greater or less pressure, and,by surrounding the wood,prevents a vacuum, (which would otherwise resultfrom the condensation of steam,) and thus prevents cracking or checkingof such wood. This having been continued for a proper length of time, Inow close all approach to the chamber J except through the steam-heatingcoil, which I do by closing the cooks 8, 9, and 3, the steam thuscirculating through the coil-in the chamber J and exhausting by the cookor outlet 4. The heat radiating from the coil serves to thoroughly drythe wood. Simultaneously with the closing of the cocks 8, 9, and 3- andthe shutting .outof the entrance of steam directly intothe interior ofthe chamber J, the cooks 10 and 11 are opened and 12 and 13 closedconsequently the pump is converted from a pressure to a suction orvacuum pump, and the vapors resulting from steam and the heat within thechamber J are withdrawn from such tank by means of pipe 0 and exhaustedthrough thefcock 11. This continues until the vapors cease toissue fromthe cook 11, (it being observed that the water-jacket of theair-cylinder. of the pump serves at this time to reduce the temperatureof such vapors,) when the cook 10, which, as will be seen, constitutesthe means of communication between the air-pump and treating-chamber,

J through pipe (3, is shut, by this means closing such communication,and the exhaust-cock 11 is also closed. 1 now open cocks 12 and 13,which permits inlet of air to the pump-cylinder, and also open cocks 9and 14, (it being understood that said pump is continually inoperation,) by which means air is forced by the pump through pipe D D D,&c., through .the cook 14 into the creosote-tank B, it being borne inmind that the cock 8 is at this time closed. The air entering the tank Bunder; pressure from the pump, aslast stated, drives the creosote orother preserving fluid from such tank into the chamber J, and forces thefluid into the pores and cells of the wood,

which are distendedand open from the action of the steam, the fluid, inits passage to said chamber J, passing through pipe E and books 16 and17, which are now opened for the first time to permit this.

As soon as the preserving-fluid in the tank B has been driven from it inthe manner last stated,fI close the cock 14, which shuts ofi'. pressureof air from the'pump to such tank,

and also shut cook 16, which closes commu nication between the tank'Band chamberJ by way of the pipe E.

I next open cook 21 theextension D? of the pipe D, which plermits airunder pressure from the pump through pipe D D D; 8150., to enter. intoand coursethrough' the injectorbarrel R, where it: unites with theexcess of fluid flowing from thebottom of chamber J through pi e F byopening coc kso and 19, and carries it with it in its course throughpipe H, cocks 18and'1-7'being open, back into the foraminous pipeswithin chamber J,jandthus forces the fluid into the cellsanjd pores ofthe wood, this circulation being continued under pressure until the woodhas taken up all the creosote or other preserving agent, or so muchthereof as may be found desirable.

When the proper pressure has been reached in the treating cylinder ortank the cooks 12 and 13 may be closed and the cock 10 opened, so as todraw the air from the tank and return it thereto through the injector.

When the pores and cells of the wood have absorbed all the treatingmaterial which it is capable of receiving, or the predeterminedquantity, whatever it may be, the air-pump is stopped, cocks 17, 18, 19,and 21, which open the communication with the air-injector R, areclosed, and cook 20 in pipe H F opened. Consequently any excess ofcreosote remaining in the chamber J not taken up by the wood is forcedback to the tank B by the pressure remaining in said chamber.

The chamber J is now allowed to cool down, the cook 20 is closed, andthe wood perfectly treated taken from such chamber.

As the action of creosote or other analogous preserving agents upon woodhas been fully alluded to in former patents issued to me, I have notdeemed it necessary to repeat the explanation in this specification. Butin the present process of treating wood and the necessary apparatusheretofore described for the purpose, it will be observed that I employsteam, at such temperature as is necessary,

I its tissues by the same.

Moreover, steam alone would cause the wood to crack and check from theexpansion caused by the heat generated in the interior of the wood,which heat is necessary to effect the evaporation of the sap. Hence Iforce into the preserving-chamber the necessary pressure of atmosphericair to prevent the wood from checking.

Wood cannot be thoroughly impregnated with creosote or otherpreserving-fluids until the sap or water is drawn out of the pores ofthe wood. Hence the methods above described are essential for thispurpose.

Moreover, in my former patents I used air for drying the wood aftersteaming; but I found in practice that it also caused the vapors tocondense on the wood; hence in my present process, while using' airnnderpress nre sufficieiitto preventcracking, I exhaust l the'vapors througha vacuum-pump, asd'eQ scribed, maintaining the necessary degreeof 1 heatto prevent condensation by' means of the "j coil of steain-pipe-"in thebottomof the preserving-chamber. l A

' Inwithdraiving tlie vapors in theimanne'r My method of introducing thepreserving finid into the treating-chamber through foraminous pipes, soarranged as to shower upon the wood from every direction, and afterwardby means of the injector, as described, keeping up a continuouscirculation of the preservingfluid, is superior to any method forsoaking wood in a vat, the fluid entering the wood more thoroughly andinsuring a perfect saturation of the wood.

Having thus described the nature, purposes, and advantages of myinvention, and the manner in which the same is or may be carried intoeffect, what I claim as my invention, and desire to secure by LettersPatent of the United States, is as follows:

1. In the process of preserving wood, the method of preparing the woodfor reception of the preservative by subjecting it in a closed tank tothe action of steam, forcing air under pressure into the tank during thesteaming operation, and then exhausting from the tank the resultantvapors, as set forth.

2. The combination, substantially as set forth, of the boiler, thewood-containing tank, and the air-pump, with their system ofconnections, arranged substantially as described, so that the pump mayact as a force-pump to maintain air-pressure in the tank during thesteaming operation, and subsequently as a vacuum-pump toexhaust from thetank the vapor arising from the action of the steam.

3. The combination of the air-pump, the wood-receiving tank, and theinjector and their connections, arranged substantially as set forth, sothat the preserving-fluid, as it passes from the tank, shall, by actionof the pump and injector, be returned to said tank, to again act on thewood therein.

4. The combination, substantially as set forth, of the wood-receivingtank, the injector, the preserving-liquid reservoir, and the pump,connected substantially as set forth, so that the pump may be used at,will to force the liquid from the reservoir to the tank, or to maintainthe liquid circulation through the injector and tank, or finally topermit thereturn of the liquid to the reservoir.

5. The combination of the wood-receiving tank, the steam-generator, thepreserving-liquid reservoir, and the air-pump and connections, operatingto maintain air-pressure in g described, Ials'o create a vacuum aroundthe a wood beingtreated-e-a condition favorable-for its full andcomplete impregnation by the pres eiving fluid, which iss u'cked intothe dry, 1

the tank during the steaming operation, to remove the steam and othervapors from the tank and to force therein the preservative liquid,substantially as set forth.

'6. The combination, with the air-pump K and chamber or retort J, of thetwo systems of pipes, D D, 860., and O Q C, 850., with their respectivecocks, substantially as herein shown, whereby such pump becomes at onetime a force-pump to drive air into the treating-chamber J, at anothertime a vacuumpump to extract vapors of the steam from such chamber andcreate a vacuum therein, and at another time a force-pump to drive thetreating-fluid from its reservoir into thetreating-chamber and the poresof the wood, and, finally, a force-pump to maintain a circulation of airand of the preserving agent throughout the preserving process,substantially as and for'purposes stated.

' IRA HAYFORD.

Witnesses: I

W. E. BOARDMAN, F. HUNNEWELL.

